Sorted it, just deleted my gmail account and reset it up, simples my credit was there plus the nexus guidebook and transformers! Don't know why it didn't work in the first instance but never mind.
Spent all of last night getting to grips with my nexus and it is fabulous. Downloaded and set up SNES and nes ROMs, the tegra designed games are great to play and visually superb.
Hmmm what to do next on it, still can't put it down!